We didn't build rockets and travel to the moon before we made airplanes.

If we had low gravity and thin atmosphere then we probably would have.

Quote (Talisman)

However I really think the drake equation is way way too strict, and assumes that civilizations destroy themselves easily, which I think is HIGHLY improbable.

The Drake equation doesn't assume anything. It's just a form for filling in numbers, an accounting of all the necessary variables to answer the question. Only the person inputting the numbers into the equation can make assumptions. I've seen people run the drake equation and get <1, and I've seen people run the drake equation and get millions, as Carl Sagan famously demonstrated in the 12th episode of Cosmos.

Quote (Talisman)

we haven't been close to extinction ever during modern times, even during the cold war

There actually were a couple of times during the Cold War when we were literally a hairsbreadth from a full nuclear exchange, which would have absolutely ended our global civilization. Whether it would have resulted in the extinction of our species or not is less clear, likely not, but that is irrelevant for the purpose of this discussion.

And the threat of catastrophe looms still today, which most people don't realize.

Completely illogical. The technical skill required to construct a lethal weapon is unrelated to the temperance and foresight necessary to avoid using it; if it was then we would never have built the weapons in the first place. You assume that people who think of using ICBMs - or other weapons - would do so with the intent of destroying humanity. That is simply not the case, they plan for it out of petty politics, spite, and occasionally insanity, usually with willful ignorance regarding the consequences.

The truth is that most humans don't really think all that much about the collective good, and have convinced themselves that they can do pretty much whatever they want and that there will be no consequences. And even if most people were good enough to overcome that inclination, the way we have the destructive power distributed in the world renders that irrelevant since all it takes is just a few crazy people to bring about the end of the world. Humanity is not the jewel of wisdom that you seem to think it is.

The Drake equation doesn't assume anything. It's just a form for filling in numbers, an accounting of all the necessary variables to answer the question. Only the person inputting the numbers into the equation can make assumptions. I've seen people run the drake equation and get <1, and I've seen people run the drake equation and get millions, as Carl Sagan famously demonstrated in the 12th episode of Cosmos.

I know what the Drake equation is. Many people just fill it in in a very pessimistic manner. I've seen it commonly done where it comes out to single digit numbers, more-so then how Sagan did it.

Quote (HarbingerDawn)

There actually were a couple of times during the Cold War when we were literally a hairsbreadth from a full nuclear exchange, which would have absolutely ended our global civilization.

I'm going to have to disagree here. There's simply not enough warheads to end civilization.

Have you seen this picture? It's a good one.

Quote (HarbingerDawn)

The technical skill required to construct a lethal weapon is unrelated to the temperance and foresight necessary to avoid using it

I'd agree, for things like muskets and swords.

Being able to successfully deploy ICBM's, MIRVS, and a tactical strike to make mutually assured destruction possible takes quite extreme intelligence, again I'm not trying to make humans out to be crusaders of wisdom, we're all just a bunch of dumb warlike simians. But being able to do that takes some wit, we all know what nukes are for. They're psychological tools these days. Every single leader of a country knows how stupid nuclear war is, that it will never happen because of mutually assured destruction, it's simply far to powerful of a weapon.

Is it just me or does that picture not take into account strategic targets and nuclear fallout?

If you targeted large population areas plus farmland you would starve a civilization by poisoning the food supply and collapse the economy by destroying major commercial area. Not to mention the collapse of infrastructure.

Seems to me its less about wiping humanity out and more about crippling the society as a whole to a point where it cannot recover.

That's really not how it works. You don't need to achieve complete destruction of every square meter of human inhabited land to end human civilization. The area in which that bomb would be lethal is up to 50 times the area in which it achieves "complete destruction". Then there's the fallout to consider. Then there's nuclear winter, which many scientists accept as a strong possibility. The loss of industry, utilities and infrastructure, emergency services, government, agriculture, transportation; most high technology would be inoperable due to EMP, etc. These are the things that lead to the downfall of social order and civilization, and these things do not require the level of destruction outlined in your image, nor do they even require the deaths of most people.

As for the number of nukes needed to end civilization: if the theory of nuclear winter first outlined by Sagan et al. is correct, then the number could be a low as 100.

Even if you say that to destroy civilization you would need to destroy every city in the world with a population of at least 100,000 then you would only need 4600 nukes.

Carl Sagan discussed these very points in an interview with Ted Turner in 1989 (you can view it here, he talks about this in parts 1 and 2).

At the MOST the lethal radius would be only 5-10 times that area. And that's if you're standing outside. Keep in mind nuclear bomb shelters exist but you can take that image and multiply the numbers as much as you logically want, it still wont be enough.

But just to humor you, let's say that it really was 50 times the area. (750 square miles of instant death lol)

You would still need 24800 nukes. Fallout is irrelevant as long as you have a shelter or any place indoors with reasonable protection.

Also keep in mind that not everyone lives in a city.

Also keep in mind that there are TONS of nutjobs that are completely self sufficient, just because you can't go to walmart and buy food doesn't mean the entire world will starve and die.

That picture still holds value, the United States conducted around 1,054 nuclear tests between 1945 and 1992, not counting Russia and other countries tests. You think 100 nukes detonated at once would cause a nuclear winter that would cause the extinction of mankind? I find it hard to believe Carl Sagan even though that.

Quote (HarbingerDawn)

As for the number of nukes needed to end civilization: if the theory of nuclear winter first outlined by Sagan et al. is correct, then the number could be a low as 100.

The United States conducted 1,054 nuclear tests between 1945 and 1992, you think if 100 nuclear warheads were detonated at once it would cause a nuclear winter (if it even caused one) that would cause the extinction of mankind? That's illogical. I find it hard to believe Carl Sagan even said that.

Quote

Even if you say that to destroy civilization you would need to destroy every city in the world with a population of at least 100,000 then you would only need 4600 nukes.

Can you elaborate on when and why that would ever happen? The biggest nuclear exchange possible would be between Russia and the USA, and they wouldn't aim for any other countries if it ever happened. Why would a single country aim for all other countries cities?

Also, there are millions of other cities around that have less then 100,000 people, you literally can't nail every single city on Earth with all of the worlds nukes, it's impossible. I hope you realize this.

You don't need that many people to re-populate the Earth.

The bottom line is, it's impossible to cause the extinction of mankind completely in any sort of logical scenario, could you kill off a large percentage? Yes. Could you cause extinction? No.

On top of that. we never had a large scale nuclear exchange. Because EVERYONE knows how that would turn out. And no one wants that to happen. And it will never happen, I'll bet you millions.

Can you elaborate on when and why that would ever happen? The biggest nuclear exchange possible would be between Russia and the USA, and they wouldn't aim for any other countries if it ever happened. Why would a single country aim for all other countries cities?

This would lead to a declaration of war form the USA's allies against Russia and Russia's allies against the USA. In a global society this would not end well at all.

Quote (Talisman)

The bottom line is, it's impossible to cause the extinction of mankind completely in any sort of logical scenario, could you kill off a large percentage? Yes. Could you cause extinction? No.

If civilization knocks itself back too much then society would never be able to recover in time to protect itself from an asteroid impact or from the sun expanding/exploding.

But that's just wrong. Can you provide a source for that statement? Or did you just make it up?

I was using some wrong numbers. Really it's 10-15 times the area. http://www.radshelters4u.com/ has some good data and graphics, the relevant one in this case is the one concerning the 1 MT air burst (B83 is 1.2 MT). The total destruction radius is barely more than one mile, but it can be lethal out to over 5 miles.

Quote (Talisman)

The United States conducted 1,054 nuclear tests between 1945 and 1992, you think if 100 nuclear warheads were detonated at once it would cause a nuclear winter (if it even caused one) that would cause the extinction of mankind?

It's not the nuclear detonations themselves that cause nuclear winter, it's the smoke and particulate matter lofted into the stratosphere by fires burning in cities.

Quote (Talisman)

I find it hard to believe Carl Sagan even said that.

You don't have to take my word for it, I posted the link to the interview where he said exactly that...

Quote (Talisman)

Also keep in mind that there are TONS of nutjobs that are completely self sufficient, just because you can't go to walmart and buy food doesn't mean the entire world will starve and die.

This has no bearing on the fate of civilization. You are confusing that with human extinction, which is a separate matter.

Quote (Talisman)

Can you elaborate on when and why that would ever happen?

I'm not saying it would ever happen, it would make no sense for it to, I'm just pointing out that that absurd worst-case number of required nukes is still less than the number of nukes on Earth.

Quote (Talisman)

Also, there are millions of other cities around that have less then 100,000 people, you literally can't nail every single city on Earth with all of the worlds nukes, it's impossible. I hope you realize this.

Again, this has no bearing on the fate of human civilization. Also keep in mind, most of these less populous areas are suburbs to the larger cities, and will be affected by the blasts there...

Quote (DoctorOfSpace)

This would lead to a declaration of war form the USA's allies against Russia and Russia's allies against the USA. In a global society this would not end well at all.

This is correct. Any attack against the USA would automatically involve NATO, which has most of the rest of the nukes.

Quote (Talisman)

And it will never happen, I'll bet you millions.

Well I won't bet against you there, but even if I did and I won I wouldn't be able to collect

Well I won't bet against you there, but even if I did and I won I wouldn't be able to collect

I wouldn't bet much money on a global nuclear exchange either (although the possibility is always there), but I think that humanity will inevitably have to deal (perhaps a better word is "cope"?) with the use of nuclear weapons, because of nuclear terrorism. I think it is only a matter of time until the US, Israel and maybe even Russia will be subject to nuclear attack by extremist groups (also, you must realize that if such an event was to happen, global tensions and mistrust would rise sharply, and any small incident or crisis could escalate to war or even a nuclear exchange).

It's not the nuclear detonations themselves that cause nuclear winter, it's the smoke and particulate matter lofted into the stratosphere by fires burning in cities.

I know, but 100 cities burning wouldn't produce enough emissions and smoke to cause a nuclear winter, would it effect the climate significantly? Probably so, but I really don't think that's enough material to completely blot out the sun for any reasonable amount of time. Even if, there are TONS of underground cities completely self sufficient, I actually watched a documentary on the cold war last night and the KGB has a giant underground city protected from nuclear attacks. The USA has a few of these as well. Not to mention privately funded bunkers capable of being self sufficient for many many years. Humans don't need sun light to live, we can grow plants with artificial light.

Quote (HarbingerDawn)

This has no bearing on the fate of civilization. You are confusing that with human extinction, which is a separate matter.

So what are you arguing for here? From what I'm getting you're trying to say that a nuclear exchange would end civilization and humans would not be able to recover at all and eventually die out.

This is just false.

Quote (HarbingerDawn)

This is correct. Any attack against the USA would automatically involve NATO, which has most of the rest of the nukes.

You think Britain and France would launch all their nukes at Russia if USA and Russia had a nuclear exchange? I highly doubt that at all because if they did that they know that Russia would have leftovers to respond with, and they wouldn't want to risk that for their population. They would help out, they would not use their nukes. A nuclear exchange between USA and Russia (Pretty much the only plausible scenario that could happen) would only involve them, the rest of the world would be shocked, but everyone wouldn't go crazy and start launching nukes to every country on Earth.

Let's say some sort of terror organization SOMEHOW was able to control all nukes in the world, and send them to targets that would cause the most devastation possible. It might result in a pretty long nuclear winter. And after long term effects probably 70-90% of the human population would be killed. But that's more then enough left to survive and preserve the knowledge of our civilization and rebuild humanity.

Quote (HarbingerDawn)

Well I won't bet against you there, but even if I did and I won I wouldn't be able to collect

Of course, and much less be able to spend any of it.

Also, don't get me wrong. I don't think nuclear weapons are all fine and dandy. But they are pretty necessary. And they have saved more lives then they have killed.

I'll go ahead and use firearms as an analogy. People will always be able to acquire guns, even if a city tries to "ban" them and make everyone stop using them, you can make your own pretty easily. Much like if all the nuclear superpowers forfeited their nuclear arms other small countries would develop their own nuclear weapons to try and gain some power.

Right now in my opinion we are past the point of ever having global thermonuclear war, they serve as a warning in the back of our mind and for countries that want to start a serious war. Try to nuke us and we will vaporize your country right back at ya.

You can't win a nuclear war (against a country with nukes). That's why we've never had a nuclear exchange. And that's why it will never happen.

From what I'm getting you're trying to say that a nuclear exchange would end civilization and humans would not be able to recover at all and eventually die out.

That's not what I'm saying. I'm saying that human civilization would end. I don't make any predictions about whether it will ever get started again, or whether humanity would go extinct. I just say that civilization ends in that scenario.

Quote (Talisman)

You think Britain and France would launch all their nukes at Russia if USA and Russia had a nuclear exchange? I highly doubt that at all because if they did that they know that Russia would have leftovers to respond with, and they wouldn't want to risk that for their population.

They would have to, because in all likelihood Russia would launch at them; it would have to assume that the rest of NATO would join in and it couldn't risk that, so it would launch preemptively. Besides, if the whole world goes to hell and people start launching nukes, why would you be so choosey? Your nation is sunk anyway, might as well take everyone else down with you. If you launch at one of your enemies, and then they launch at you, and there's a possibility that your other enemies might as well, then you'll launch at them. You don't have much to lose at that point, and the people in charge in such a scenario are likely less than rational.

Quote (Talisman)

And after long term effects probably 70-90% of the human population would be killed. But that's more then enough left to survive and preserve the knowledge of our civilization and rebuild humanity.

I think that's a little optimistic. More people than that would probably be killed, they'd be hard pressed to find any food with agriculture now practically impossible, and the effects of nuclear winter and fallout would last for generations. You would be unable to preserve more than a tiny fraction of human knowledge.

Look at the fall of classical western civilization. That was an event of very minor magnitude compared to what we're talking about, and yet the vast majority of knowledge possessed by that civilization was lost, and human progress was set back by nearly a thousand years. Much more would have been lost if it weren't for other independent civilizations helping to preserve what little was left, notably Islamic scholars. A nuclear apocalypse would be far more severe. People would be far less organized, far more concerned with basic survival, and would lack the means of preserving the information, means that people had access to in the first millennium.

And where do you get that power from? Most of the infrastructure would be gone, and fuel for generators would be limited, as would replacement parts as the generators themselves failed after decades of prolonged use.

Quote (Talisman)

You can't win a nuclear war (against a country with nukes). That's why we're never had a nuclear exchange. And that's why it will never happen.

Some people just don't care whether they win or not. Some people just act out of rage or spite or plain insanity. All your assumptions about nuclear war not ever happening presuppose that everyone in charge of the nuclear arsenals is intelligent, logical, rational, and committed to the survival of humanity. This is just not the case.

Quote (Talisman)

And they have saved more lives then they have killed.

Anything that is in the position to cause as much harm as those weapons can should not exist. I'm not saying that we should eliminate all nuclear devices from the world, but having thousands of nuclear weapons deployed and ready to launch on a moment's notice is clearly not a good idea, and instead of making excuses about how the present global political climate requires their existence, we should work aggressively to change that climate so that we can get rid of them.

why would you be so choosey? Your nation is sunk anyway, might as well take everyone else down with you.

Lol? I can guarantee you no missile commander would ever think like this, I hope that was a joke.

Quote (HarbingerDawn)

They would have to, because in all likelihood Russia would launch at them

This is just baseless speculation. No one is eager to get in a nuclear war at all, Russia for sure would be only wanting to attack the USA (If somehow a nuclear war happened much like the cold war)

They don't have enough nukes to just toss them around wherever they want. They would use most of their missiles for the USA. Probably 70% of their arsenal to fully attempt to destroy the United States and it would be devastating, they would issue a message to all other countries stating they would be obliterated if they sent nukes as well or got involved. No one would want to get into that situation.

More pessimistic predictions argue that a full-scale nuclear war could potentially bring about the extinction of the human race, or at least its near extinction, with only a relatively small number of survivors (mainly in remote areas) and a reduced quality of life and life expectancy for centuries afterward.

Those are very pessimistic views, yet they still admit that it would be very hard for a full-scale nuclear war to extinct us.

Quote (HarbingerDawn)

I'm saying that human civilization would end. I don't make any predictions about whether it will ever get started again, or whether humanity would go extinct. I just say that civilization ends in that scenario.

Can you define what you mean by "civilization ending"?

I define civilization ending as 100% of humans dying. ( A civilization is not the same thing as civilization as a whole )

Even if 90% are killed the 10% continues to live, survive and, expand. That doesn't mean civilization ended and started again. That means it was just reduced as it continued along.

Quote (Harbringer)

the vast majority of knowledge possessed by that civilization was lost, and human progress was set back by nearly a thousand years.

Human progress wasn't set back a thousand years. THAT CIVILIZATIONS progress was set back by nearly a thousand years. That civilization didn't include all humans.

I wonder when Space Engineer comes back from his trip. I want to hear his views on this subject as a Russian.

Those are very pessimistic views, yet they still admit that it would be very hard for a full-scale nuclear war to extinct us.

Again, I don't think that a nuclear war would lead to the total extinction of humanity. I don't know how many times or in how many different ways I need to say this. Extinction is irrelevant to this discussion.

Quote (Talisman)

Can you define what you mean by "civilization ending"?

I suppose that this discussion would have benefited greatly if we had defined the word "civilization" at the outset. I had thought that we were all on the same page, I'm sorry I wasn't more clear. Civilization is a difficult term to define, but I will do my best.

A civilization is a collective of sentient beings that contains division of labor and specialization, a surplus of food (wealth) to be used in support of such specializations (government, military, scholars, doctors, etc.), a large area influenced by its specializations (technological, military, artistic, and religious), and maintains continuity of collective knowledge. This type of collective would usually contain at least one city.

The key is that the society supports the existence of specialized individuals, who perform the tasks of record keeping, medicine, defense, government, etc., that could not survive on their own without forgoing their specializations.

So any world in which nearly everyone is concerned with survival and finding food could not possibly be civilized, since there would be no government, no infrastructure, no art, no intellectual pursuits, and no one to organize, preserve, and add to the sum of human knowledge, for in such a world anyone who attempted to do these things would starve to death.

Quote (Talisman)

I wonder when Space Engineer comes back from his trip. I want to hear his views on this subject as a Russian.

Probably not all that dissimilar from some perspectives you hear from Americans (of which there are many). But I would be interested in his input as well anyway.

because of nuclear terrorism. I think it is only a matter of time until the US, Israel and maybe even Russia will be subject to nuclear attack by extremist groups (also, you must realize that if such an event was to happen, global tensions and mistrust would rise sharply, and any small incident or crisis could escalate to war or even a nuclear exchange).

1. If it is impossible to move at the speed of light, because it takes infinite energy to reach the speed of light..... then how is light moving at the speed of light?

Photons have no rest mass, even though they are influenced by gravity somewhat (gravitational microlensing, black holes etc)

Therefor they can somehow travel at the speed of light. I'm sure Harbinger can offer more insight on photons.

Quote (anonymousgamer)

2. Wasn't it discovered that some particles can in fact move faster than light?

Unfortunately the neutrinos thing was just an error, they repeated the tests and from what I've heard found that they don't move faster then light.

Quote (HarbingerDawn)

I suppose that this discussion would have benefited greatly if we had defined the word "civilization" at the outset.

Indeed, my mistake, I thought you meant all of civilization.

Quote (HarbingerDawn)

So any world in which nearly everyone is concerned with survival and finding food could not possibly be civilized

How did we become civilized then?

Keep in mind there are many remote servers, databases hidden away with the entire Wikipedia library, I don't think people would revert down to the stone-age if a large percentage of the population was destroyed. Would it be a horrible set back and tragedy for the world that would take many many years to overcome? Yes. Would a logical nuclear exchange be survivable for humans as a whole? Yes.